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Although scientists still do not know exactly what causes most
cases of soft tissue sarcoma, they have identified several risk factors
that can make a person more likely to develop these cancers. And recent
research has shown that some of these risk factors affect the DNA of
cells in the soft tissues.
Researchers have made great progress in understanding how
certain changes in DNA can cause normal cells to become cancerous. Our
DNA carries the instructions for nearly everything our cells do. We
usually look like our parents because they are the source of our DNA.
However, DNA affects more than the way we look.
The DNA is divided into units called genes. Genes carry
the recipes for making proteins, the molecules that determine all cell
functions. Some genes contain instructions for proteins that control
when our cells grow and divide.
Certain genes that promote cell division are called protooncogenes.
Others that slow down cell division or cause cells to die at the right
time are called tumor
suppressor genes. Cancers can be caused by DNA mutations (defects)
that turn on protooncogenes or turn off tumor suppressor genes.
Several familial cancer syndromes have been found in which
inherited DNA mutations cause a very high risk of developing breast,
colon, kidney, eye, or other cancers. In some of these, there is also
an increased risk of developing soft tissue sarcomas. Researchers have
characterized many of these DNA changes in the past few years.
Some inherited conditions that increase a person's risk of
developing soft tissue sarcoma were noted in the section on risk
factors. They are caused by defects (mutations) in genes that can be
inherited from a parent. These gene defects can be found through
genetic testing.
DNA mutations in soft tissue sarcoma are common. They are
usually acquired during life rather than having been inherited before
birth. Acquired mutations may result from exposure to radiation or
cancer-causing chemicals. In most sarcomas, they occur for no apparent
reason.
Researchers still do not know why most soft tissue sarcomas
develop in people who have no apparent risk factors.
Last Medical Review: 03/03/2009
Last Revised: 05/14/2009
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